Once you receive your new device you will have the opportunity to transfer your data (accounts, photos, contacts, apps etc) to the new device using Apple's Quick Start feature: https://support.apple.com/en-gb/102659
As part of this you can transfer your SIM as an eSIM, or choose "Set Up Later" and just swap across the physical SIM Card from the old phone to the new phone (physical SIMs are easier to work with, so I would avoid transferring your plan/SIM when prompted to do so by the setup process and just wait until you've got the new phone fully set up first)
